Diff between some carbs

[Nacho-RT74]

Ok... I FOUND A CARB DEALER HERE WITH TONS OF TQ CARBS AND ANOTHER OLD RARITIES.

my car apparently had from fact ( is the one installed on my car since I bought from owner ) the 6140 what apparently is for 400 but manual tranny as this website says:

http://www.thecarburetorshop.com/Kdodge.htm

what could it be the difference between a carb to manual tranny or auto tranny ? ( this is the first question I want to clarify )

I'm thinking on another options to my car if dealer have them none with calif restrictions because my car doesn't have any part of emission controls, just dist port, PCV port, Air cleaner air entries port and choke port:
72 auto: 6090
73 auto: 6321
74 auto: 6457
             6503
             9014

By now I confirmed that dealer has a rebuilt in USA 6140, but I want to check if he has the others ones, and decide wich one choose.

If you know which one could it be the best to my car please tell me and why... ( this is the second question )

P.S.: I already am sending this thread to demonsizzler hoping he reads this thread and also helps.

[Chryco Psycho]

the settijng of the rear air door wil be different between 4 spd & auto
Demon is th eguy to ask from what I hear